Masayoshi Son cranks up his battle for T-Mobile

Japan's wealthiest person has been trying convince U.S. regulators to allow Sprint, the No. 3 wireless carrier, to acquire T-Mobile (TMUS). But so far, he has failed to persuade them.

Now, Son is taking his case directly to the American people, saying in TV interviews on "The Charlie Rose Show" and on CNBC that Americans pay too much for broadband service that, at least compared with the rest of the world, is slower than molasses.

When regulators rejected AT&T's (T) $39 billion acquisition of T-Mobile in 2011, they made it clear they wanted four national wireless carriers. Even though the odds are stacked against Son, independent telecom analyst Jeff Kagan argues that investors shouldn't count him out. After all, some pundits were skeptical that regulators would approve Softbank's $21.6 billion takeover of Sprint, and that got approved.

"That's the million dollar question that no one has the answer to, not even Masayoshi Son," says Kagan. "I can't see the regulators on their own choosing to allow the merger, but I wouldn't put anything past Masayoshi Son. He has a way of winning people over and getting his way."

If Son is successful, he vows to launch a "price war" against rivals Verizon (VZ) and AT&T, the No. 1 and 2 players, respectively. Shares of Verizon and AT&T didn't really budge after Son went on TV because the companies are already in the midst of a growing price war with T-Mobile.

Under the leadership of outspoken CEO John Legere, T-Mobile has upended the staid wireless industry through aggressive marketing, including one program in which the company pays consumers' costs to "break up" with their existing carriers. The industry has been forced to react to Legere's strategy, which has helped T-Mobile snag 869,000 monthly customers in the last quarter, far more than its rivals and ahead of Wall Street's expectations.

AT&T announced on Tuesday that it would slash the costs of some data plans used by families and small businesses by $15 a month. Last month, Verizon unveiled its "more everything" plan offering customers more data for their money in an effort to keep them from defecting.

The price wars are only going to intensify because the U.S. wireless market is at a saturation point, meaning the only way the combatants can grow is by stealing each other's customers.

Of course, Son is well aware of the market's harsh realities and is wealthy and patient enough to wait for regulators to see things his way. By Kagan's reckoning, it's not a question of if the billionaire buys T-Mobile, but when.